Jakob Nielsen (mathematician)
Jakob Nielsen (born October 15, 1890 in Mjels , Alsen , † August 3, 1959 in Helsingør ) was a Danish mathematician who became known for his work on the automorphisms of surfaces .
Life
Nielsen was born in the village of Mjels on the island of Als in Northern Schleswig , which at the time was part of the German province of Schleswig-Holstein . His mother died when he was 3 years old, so from 1900 he lived with his aunt and started school in a high school. In 1907 he had to leave school because of his membership in an illegal student club. Nevertheless, he enrolled at the University of Kiel in 1908 .
In 1913, Nielsen completed his doctoral thesis, soon after he was drafted into the German Imperial Navy . He was assigned to the coastal defense. In 1915 he was transferred to Constantinople to the German military mission in the Ottoman Empire . After the war, in the spring of 1919, he married Carola von Pieverling, a German doctor.
In 1920 Nielsen took up a position at the Technical University in Breslau . The following year he published an article in the journal Mathematisk Tidsskrift in which he proved that any subgroup is free from finitely generated free groups . In 1926 Otto Schreier generalized this knowledge by removing the condition that the free groups are finite generated; this realization is also known as the Nielsen-Schreier theorem. In 1921 Nielsen went to the Royal Veterinary and Agricultural University of Copenhagen, where he stayed until 1925, and then moved to the Technical University in Copenhagen.
Attempts to bring Nielsen to the United States were made during World War II because of fear that he would be captured by the Nazis. However, Nielsen stayed in Denmark without being bothered by the Nazis.
With Werner Fennel he is the namesake of the Fennel-Nielsen coordinates in the Teichmüller area . Fennel also published his Collected Writings. The realization problem by Nielsen (1932) was from the early 1980s Steven Kerckhoff solved.
In 1951 Nielsen became professor of mathematics at the University of Copenhagen after this position was vacated by the death of Harald Bohr . He gave up this position in 1955 because of his international obligations, particularly those at UNESCO , where he was a board member from 1952 to 1958.
In 1936 he gave a plenary lecture at the International Congress of Mathematicians in Oslo (topology of surface maps).
See also
literature
- Werner Fennel: Jakob Nielsen in memoriam . In: Acta Mathematica . tape 103 , no. 3-4 . Springer Netherlands, June 1960, ISSN 0001-5962 , p. IV-XIX , doi : 10.1007 / BF02546355 .
Fonts
- Lectures on elementary mechanics , basic mathematical science . Springer Verlag, 1935 (edited by Werner Fenchel)
- The structure of periodic transformations of surfaces . In: Mat.-Fys. Medd. Kgl. Danske Vid. Selsk. , 15, 1937
- The group of three-dimensional lattice transformations . In: Mat.-Fys. Medd. Kgl. Danske Vid. Selsk. , 5, 1924
- Surface transformation classes of algebraically finite type . In: Mat.-Fys. Medd. Kgl. Danske Vid. Selsk. , 21, 2, 1944
- Nielsen: Collected Mathematical Papers. edited by Vagn Lundsgaard Hansen. 2 volumes, Birkhäuser, Basel a. a. 1986, ISBN 3-7643-3152-6 . ( Review by Jane Gilman in BAMS 1989 with discussion of the connection with the work of Thurston )
- with Werner Fenchel : Discontinuous Groups of Isometries in the Hyperbolic Plane , ed. Asmus L. Schmidt , De Gruyter Studies in Mathematics 29, De Gruyter 2003, ISBN = 3-11-017526-6, books.google.de
Web links
- John J. O'Connor, Edmund F. Robertson : Jakob Nielsen (mathematician). In: MacTutor History of Mathematics archive .
| personal data | |
|---|---|
| SURNAME | Nielsen, Jakob |
| BRIEF DESCRIPTION | Danish mathematician |
| DATE OF BIRTH | October 15, 1890 |
| PLACE OF BIRTH | Mjels , Alsen , North Schleswig, Schleswig-Holstein Province, German Empire |
| DATE OF DEATH | 3rd August 1959 |
| Place of death | Elsinore , Denmark |